Owing to sufficient flexibility and buffering property, a polyethylene-based resin laminated foam sheet (hereinbelow, also referred to as a foam sheet) can prevent a damage or a scratch of a packaged material, and thus it is widely used as a material for packaging home appliances, glass instruments, ceramic wares, or the like.
Furthermore, in accordance with a development of a thin type television and an increasing demand therefor in recent years, a polyethylene-based resin laminated foam sheet having an anti-static layer is used as an interleaf disposed between glass plates to prevent a damage on a surface of glass plate during packaging or conveying of a glass plate for an image display device such as liquid display, plasma display, or electroluminescence display (Patent Literatures 1 and 2).
Until now, as a glass plate used for an image display device such as liquid crystal panel, glass plates with various thicknesses have been developed. Recently, from the viewpoint of having light weight, saving energy, and reducing production cost or the like, a very thin glass plate of which thickness is 0.5 mm or less is also produced. If a conventional thick foam sheet with thickness of 1 mm to 2 mm is used as an interleaf of such thin glass plate, not only the loading efficiency is lowered but also the thickness of the interleaf becomes excessively thick relative to glass plate, and thus there is also a possibility of having breakage of a glass plate depending on the mode for load application.
For such reasons, as an interleaf for responding to such glass plate with low thickness, a development of a foam sheet with low thickness has been made. However, a problem occurs in that, when it is tried to produce a foam sheet with low thickness, it is easy to have a small hole or a through hole occurred in the foam sheet.
To cope with the above problem, the present inventors previously developed a polyethylene-based resin laminated foam sheet having average thickness of 0.5 mm or less based on the use of a special foam adjusting agent (Patent Literatures 3 and 4).
Even with the average thickness of 0.5 mm or less, the polyethylene-based resin laminated foam sheet has high quality in which an occurrence of a small hole or a through hole is prevented and suppressed, and it has an excellent anti-static performance and an excellent buffering property.